The present invention provides a lightweight portable cylindrical object retention apparatus with enhanced frictional engagement which allows one to easily load and transport cylindrical objects in a manner that minimizes movement of the cylindrical objects during transport.
The present invention is comprised of a series of elongate longitudinal tank support tubes connected together via flexible elongate connecting cables. The support tubes, in combination with the connecting cables, form multiple separate bays or cradles to receive, retain, restrain and support two cylindrical objects. As a cradle is loaded with a cylindrical object, e.g., a scuba tank or oxyacetylene tank, the connecting cables at either end flex and bow to conform to the curved profile of the cylindrical object. The cradles have lateral spans sufficient to snugly receive, capture and restrain the cylindrical object without allowing the cylindrical object to rest on the horizontal surface beneath the retention apparatus. This feature ensures that the entire weight of the cylindrical object is used to maximize functional engagement between the object, the apparatus and the underlying horizontal surface.
For simplicity and clarity throughout the remainder of this disclosure, the class of cylindrical objects will be referred to as "tanks." However, the present invention is intended to accommodate and be used for safely transporting both hollow cylindrical objects, e.g., tanks or pipe, as well as solid cylindrical objects.
The support tubes, connecting cables and resulting cradles of the retention apparatus are sized to prevent a tank loaded in a bay from actually resting on the horizontal surface below the tank support tubes. This causes the entire weight of a loaded tank to be supported by the adjacent tubes. Hence, the tank weight is used most efficiently to maximize the frictional engagement between the wall of a tank and the support tubes. This novel design also maximizes the frictional engagement between the tank support tubes and the horizontal surface upon which the tubes rest. Frictional engagement is further enhanced by the inclusion of a rubberized covering, with superior frictional characteristics, which is wrapped about the exterior mid-section of each longitudinal tank support tube.
Cylindrical tanks, including scuba tanks, oxyacetylene gas cylinders and the like, are known to be transported in vehicles while laid flat on a horizontal surface or bed of a vehicle without any form of appropriate restraint system. The vehicle bed may be the floor of the trunk of an automobile, the cargo section of a pick-up truck, the deck of a boat, or any other flat horizontal surface of any other vehicle which might be used to transport cylindrical tanks.
Once the tanks are laid on the bed or cargo deck of a vehicle or vessel, a person transporting the tanks will frequently use temporary means of restraining tank movement. Objects readily at hand, which are typically ill-suited for the purpose, may be wedged between the tanks to both limit their movement and act as a cushion between the tanks and/or the cargo area of the vehicle. Unfortunately, this approach does not adequately secure the tanks for transport. Where tanks are carried in the bed of a pickup, as opposed to the trunk of a car, the substantial volume of the pick-up cargo area may further complicate this free-form tank stowage and transport method. This is especially true on a boat deck.
Additionally, by simply laying tanks on the bed of a vehicle or on a boat deck, the frictional engagement between the tanks and the underlying horizontal surface is typically insufficient to prevent the tanks from sliding about during transport. Tank cylinders are typically made of steel or aluminum. Hence, the frictional engagement between the exterior of a tank and the surface of the bed of the vehicle or boat deck is usually very low. In addition, readily available objects used to wedge the tanks to prevent movement have a tendency to dislodge. Once dislodged, the cylindrical tanks are free to both roll and slide in the bed of the vehicle or boat deck during transit to the desired destination.
Unrestrained tank movement during transport can create a severe safety hazard. Typical tanks are sufficiently heavy, whether empty or full, that their unrestrained movement in the cargo area of the vehicle or boat may cause extensive damage to both the vehicle or boat and adjacent tanks. Unrestrained tanks have been known to break off their valve heads due to movement within the cargo area during transport. If the tank is full of pressurized gas, the result can be deadly. The high pressure gas will escape through the orifice created by the broken valve head. As a result, the tank can become a deadly projectile, propelled by the jet of pressurized gas.
As an alternative to the above haphazard stowage method, various types of rigid racks have been used to stow and secure cylindrical tanks for transport in vehicles or on boats. Permanent and quasi-portable rigid racks made of steel, aluminum or other sufficiently robust and rigid material have been used to positively mount cylindrical tanks within a vehicle. These rigid tank racks include structural frames which enclose and surround the tanks. Tank racks of this type may hold the tanks in either a vertical or horizontal orientation. Examples of these rack types include those taught by Gerhard (U.S. Pat. No. 4,060,174), Smith (U.S. Pat. No. 4,175,666) and Ziaylek (U.S. Pat. No. 4,391,377).
Rigid frame-type tank racks tend to be heavy, bulky and cumbersome. Further, these rigid tank racks sometimes require substantially permanent installation in the transport vehicle. Additionally, most "removable" tank racks of this type may still require partial installation of at least some component parts, such as mounting brackets.
Additionally, many rigid tank racks require that the tanks be stowed in a vertical upright position during transport. Examples of these rack types include those taught by Hadachek (U.S. Pat. No. 5,025,935), Rohatensky (U.S. Pat. No. 4,168,007) and Cummings (U.S. Pat. No. 5,299,721). In these racks, a tank's center of gravity is at a much higher elevation than when laid in a flat horizontal position. Consequently, as a vehicle or boat changes direction while transporting the tanks, e.g., by turning a corner, existing momentum of the tanks creates amplified tipping moment.
The amplified tipping moment may subject the vertically-orienting rack to substantially greater lateral forces than when the tanks are laid flat. Therefore, these types of tank racks must be constructed to resist the increased lateral forces generated during transport. Consequently, the size and weight of these racks naturally increases as thicker heavier members are used in the frame to accommodate the increased lateral forces.
Transporting tanks in an upright position may have other disadvantages. For example, the cargo area of the transport vehicle or boat must have sufficient headroom to accommodate the height of the tanks. Hence, the trunk of many cars might be too shallow to transport scuba tanks in an upright position. Likewise, the bed of a pickup with a cargo cover could preclude the use of a vertical rack system for oxyacetylene supply cylinders.
Lastly, rigid frame-type rack systems may have footprints that are larger than the footprints of the tanks themselves. Hence, valuable floor, deck or bed space is consumed by the rack which could have been used for storage of associated equipment.
Hence, rigid frame-type racks do not readily lend themselves to occasional use. A sports person would likely be disinclined to use a rigid frame-type rack. For this periodic need, rigid frame-type racks are extremely inconvenient and insufficiently portable.
As an alternative to the rigid tank racks discussed above, A-Plus Marine Supply, Inc. of Gulf Breeze, Fla., provides connected cylindrical foam pads to lay longitudinally adjacent a tank placed in a horizontal position on the bed of a vehicle. This foam pad system provides some cushioning, but fails to adequately restrain the tanks during transport. The surface of the foam pads is smooth and slippery; the pads do not effectively frictionally engage either the tanks themselves or the horizontal surface of the vehicle bed. Further, the foam pad system does not take advantage of the weight of the tanks to maximize frictional engagement between the tanks, the foam pads or the bed of the vehicle. Hence, the tanks may still easily slide linearly on the pads during vehicle acceleration or deceleration. In addition, the foam pads are readily deformable and present little rolling resistance to the tanks. Lateral tank momentum generated during transport may easily cause a tank to compress and roll over a foam pad.
Consequently, the foam pad system does not restrain tanks sufficiently to allow one to confidently transport the tanks without additional retention means. This system also does not provide for simple adjustment to accommodate tanks of varying diameters. Hence, range of use is limited to specific tank sizes.
Accordingly, a need exists for a simple, compact, lightweight, low-cost and portable cylindrical object retention apparatus that can be easily used to restrain cylindrical objects during transport while the cylindrical objects are laid in a prostrate position on the horizontal surface of a vehicle or boat. A correlative need exists for such a retention apparatus with superior frictional engagement attributes to minimize and resist stowed tank rotational and translational movement. A further need exists for such a retention apparatus where the structural configuration provides sufficient rolling resistance to further resist tank rotational movement.